Enhanced seismic surveying

Abstract

Embodiments of the present invention help in the processing and interpretation of seismic survey data, by correlating or otherwise comparing or associating seismic data obtained from a seismic survey with flow information obtained from a well or borehole in the surveyed area. In particular, embodiments of the present invention allow for flow data representing a flow profile along a well that is being monitored by a distributed acoustic sensor to be determined, such that regions of higher flow in the well can be determined. For example, in the production zone the well will be perforated to allow oil to enter the well, but it has not previously been possible to determine accurately where in the production zone the oil is entering the well. However, by determining a flow rate profile along the well using the i)AS then this provides information as to where in the perforated production zone oil is entering the well, and hence the location of oil bearing sands. This location can then be combined or otherwise correlated, used, or associated with petroleum reservoir location information obtained from the seismic survey, to improve the confidence and / or accuracy in the determined petroleum reservoir location.

Description

TECHNICAL FIELD[0001]The present invention relates to a method and system which provides for enhanced seismic surveying techniques, and in particular in some embodiments by correlating or otherwise comparing or associating seismic data obtained from a seismic survey with flow information obtained from a well or borehole in the surveyed area.BACKGROUND TO THE INVENTION AND PRIOR ART[0002]Seismic surveying for the exploration of hydrocarbon reserves is well known in the art, and involves the use of reflection seismology to detect and map geologic features characteristic of petroleum reservoirs. A large aspect of seismic surveying is the post-processing and interpretation that is applied to the obtained seismic data, to identify the presence of oil bearing sands underneath a trap and seal, and to map the extent and depth of a detected reservoir. Any significant development that can help with the post-processing and interpretation of seismic data to provide improved results can be very ...

AI Technical Summary

Benefits of technology

The present invention provides a new technique for processing and interpreting seismic survey data by correlating it with flow information obtained from a well. This helps to determine the location of oil or gas in a reservoir. The invention also addresses the problem of quiet wells making flow detection difficult, by using externally generated noise to artificially acoustically "illuminate" the structure being monitored and collect data. This technique can increase the signal to noise ratio and provide accurate data even from quiet, low flow wells.

Problems solved by technology

For example, in the production zone the well will be perforated to allow oil to enter the well, but it has not previously been possible to determine accurately where in the production zone the oil is entering the well.

This can increase the signal to noise ratio considerably.

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